1. Field of the Invention
The present invention relates to systems and methods for the destruction of adipose tissue (fat).
2. Description of the Prior Art
Body sculpting has developed into a highly sought after procedure for reducing a person's weight and restoring people to a leaner, trimmer physique. The field of cosmetic surgery has ballooned considerably with developments in both tools and techniques. One popular procedure for both quick weight loss and body sculpting is liposuction.
Liposuction is a method of body contouring that can dramatically improve the shape and contour of different body areas by sculpting and removing unwanted fat. More than 200,000 liposuction procedures are performed annually. Recent innovations and advances in the field of liposuction include the tumescent technique and an ultrasonic assisted technique. Traditional liposuction was done by making small incisions in desired locations, then inserting a hollow tube or cannula under the skin in the fat layer. The cannula is connected to a vacuum and the fat is vacuumed out under high suction pressure. This procedure indiscriminately removed fat, connective tissue, blood vessels and nerve tissue. The procedure caused bleeding, bruising, trauma, and blood loss, restricting the amount of fat removal possible.
The Tumescent technique allows for removal of significantly more fat during the operation with less blood loss. Tumescent liposuction injects a fat layer with large amounts of saline and adrenalin solution before suctioning. A cannula is again used with a suction device to remove fat. This procedure reduces the bleeding of traditional liposuction. However the procedure still removes a significant amount of structural tissue, blood and nerve endings.
The most recently approved innovation is Ultrasound Assisted Lipoplasty (UAL). UAL utilizes a titanium cannula that has the tip vibrating at ultrasound frequency. This vibration disrupts the near volume fat cells and essentially liquefies them for easy removal. UAL uses a low power suction and draws the fat material only in the near vicinity of the cannula tip. This technique is more refined and gentle to the tissues, there is less blood loss, less bruising, less pain, and a significantly faster recovery.
The use of ultrasound for surgical procedure is not restricted to UAL. High intensity focused ultrasound (HIFU) techniques have been employed by others for cancer therapy.
U.S. Pat. No. 6,309,355 to Cain et al., discloses a method of generating micro-bubbles in a target tissue and then using an ultrasound source to cause the micro bubbles to create a cavitation effect to destroy nearby tissue. The preferred embodiment utilizes a low frequency ultrasound source (less than 500 kHz) to cause the cavitation. A diagnostic instrument is used to determine the location of the individual surgical lesions.
PCT application WO 02/054018 A2 to Eshel, et al., provides for a method of lysing adipose tissue in a region of the human body while simultaneously not lysing non-adipose tissue. The method describes the use of HIFU in the body coupled to a diagnostic imaging system and a computer to track the areas being irradiated with HIFU energy.
There have been several innovations in the development of HIFU over the past decade. Intensities have been increased to a point where boiling occurs in a very short period of time (˜1 second) as bubbles are formed from cavitation. Bubbles greatly increase the absorption of ultrasound and concomitant rapid heating of tissue. The Haifu (Chongqing, China) company has produced a therapy device for the treatment of solid tumors using ultrasound. Ultrasound energy is applied while an applicator is moving within a water bag surrounding a tumor containing tissue.
Other treatment regimens rely primarily on thermal mechanisms to necrose tissue. Several papers report creating cavitation in tissue without necessarily increasing tissue temperatures to necrotic levels. These methods apply high intensity continuous wave (CW) ultrasound regimens to tissue in order to create cavitation bubbles (sometimes referred to as “stable” cavitation), the primary purpose of these bubbles is to enhance absorption and decrease heating times. Applying therapy with very high intensity short pulses which are rapidly repeated similar to pulse wave (PW) ultrasound can create cavitation bubbles with generally very short lifetimes (micro seconds). These bubbles cause significant mechanical damage to tissue that can be periodically repeated by short (˜5-30 second) pulses without a lot concomitant tissue heating. Soliciting regimen parameters carefully can enhance mechanical damage through shear forces, transient cavitation shock waves, or stable cavitation pressures for example without necessarily heating tissue to thermal necrosis levels.
HIFU therapy can be applied several ways and combination of ways. Most HIFU regimens have been applied by locating the HIFU application at one spot and turning on the power for a given period of time, typically 1 to 4 seconds. Intensity levels are typically chosen so as to heat tissue at the focal point of the applicator to the point of coagulative necrosis, although others report heating the tissue past the boiling point of water (100 C). After a period of insonification, the applicator is turned off and moved to a new location; typically a few mm away from the previous application. The applicator is not turned on again until the tissue has had a period of time to cool, which can be anywhere from a few seconds to a few minutes. The applicator is turned on again and a new lesion is created. Treating a large volume of tissue can take hours with such an approach.
The following additional references are relevant in the art: U.S. Pat. Nos. 5,769,790; 6,113,558; 5,827,204; 5,143,063; 5,219,401; 5,419,761; 5,618,275; 6,039,048; 6,425,867; 5,928,169; 6,387,380; 6,350,245; 6,241,753; 5,526,815; 6,071,239; 5,143,063; 6,685,639 and WO 00/36982.
The above mentioned references discuss ultrasound technology relevant to the present invention, and methods of using them to destroy tissue within a person's body. However there is a noticeable short coming among the prior art. There is no teaching for allowing a patient and a physician to work together to plan a desired body sculpting plan to achieve a result the patient will find desirable. There is no means in the prior art for storing information accurately from one treatment session to the next as to what has been done in a patient. This necessitates that all treatment be done at one time, which creates the possibility a patient will be over treated, or the physician must guess by either feeling or looking at a patient's adipose tissue regions to determine what has been done in a previous session. Where a patient has undergone a non-invasive HIFU treatment, the physician will be completely lost and unable to determine what appropriate follow on treatment is desired.
Furthermore the ultra sound procedures of the prior art suffer from the ability to treat large volumes of tissue quickly. Thus as far as treating volume or mass quantities, invasive procedures are preferred.
Therefore it is an object of the present invention to provide for a means through which a patient and physician can determine an appropriate therapy treatment and get a sense for the results achievable.
It is further an object of the present invention to provide a means for the accurate determination of a the volume of adipose tissue in a patient.
Still another objective of the present invention is to provide a means for the precise tracking of therapy procedures and their effects in a patient so a patient may spread the course of a desired therapy out over time to reduce or eliminate the discomfort and danger of doing a large scale procedure all at one time.
It is further an objective of the present invention to provide a means for the accurate mapping of surgical legion placement within a human body.
It is still further an objective of the present invention to provide for means and methods for the rapid destruction of adipose tissue in volumes similar to those of invasive procedures.
Any one or more of these objects are addressed in the following disclosure.